My coworker's cousin has a JK Unlimited Rubicon and he let me drive it
last night.  I can't say I was disappointed, although it was way too
nice inside for my taste.
It has an auto tranny, he said he ordered a six speed first, but it was
too anemic so he sent it back.
With the auto, it seemed to have plenty of get-up-n-go.
The 17" rims are absurd, luckily he's lifting it and throwing 35"s on
15" rims on it.
Apparently, he can fit the 35s with only 3" of lift.  He said 37s would
fit with a 4" lift.  I don't know what kind of suspension travel that
allows or what kind of rubbing that would do with full stuff, though.  I
imagine it requires some fender hacking, too.
I can't imagine putting 37s on with everything else being stock, but I
think it's pretty cool that it's possible.